Only phpfina feeds interval needs to be shown in feeds page hover-over info box

[pb66]

It's perhaps a little misleading, certainly not useful info to state a phptimeseries or virtual feed are 1s interval.

If feed type is moved to hover-over info box (see #1027) then perhaps the interval should only be revealed for PHPFINA feed types eg

emontx : voltage
Feed ID: 77
Feed Type: PHPFINA (5s)
Feed Start Time: Monday, 5 Febuary 2018 08:12

and

emontx : voltage
Feed ID: 77
Feed Type: PHPTIMESERIES
Feed Start Time: Monday, 5 Febuary 2018 08:12

(See https://community.openenergymonitor.org/t/thoughts-on-the-new-input-and-feed-page-layouts/8583?u=pb66)

[TrystanLea]

Great! happy for this change, certainly would reduce confusion